---
title: A page with duplicate IDs
slug: Web/Duplicate_IDs
---

<h2 id="Foo">Foo</h2>

<p>Case on the <code>id="..."</code> should not matter.</p>

<h2 id="foo">Foo (again)</h2>

<p>
  This second <code>id="foo"</code> is a duplicate but it can't and shouldn't
  become <code>foo_2</code> because that's already present further below.
</p>

<h2 id="Foo_2">Foo (second again and attempted to be fixed)</h2>

<p>Text</p>

<h2 id="fOO">Foo (one last time)</h2>

<p>This last one makes sure the increment is really working</p>
